Machining process of high-strength light-weight cross shaft

Abstract

The invention relates to a machining process of a high-strength light-weight cross shaft, and belongs to the technical field of universal joint transmission shafts. The high-strength light-weight universal joint pin comprises a universal joint pin body and four universal joint pin heads, the four universal joint pin heads are arranged in a circumferential array mode and are of an integrated structure with the universal joint pin body, and the axes of the adjacent universal joint pin heads are perpendicular to each other; the universal joint pin comprises a universal joint pin body, four universal joint pin heads are arranged on the universal joint pin body, the four universal joint pin heads comprise the first universal joint pin head, the second universal joint pin head, the third universal joint pin head and the fourth universal joint pin head, the first universal joint pin head and the third universal joint pin head are coaxially arranged, and the second universal joint pin head and the fourth universal joint pin head are coaxially arranged. And the four positioning bosses on each side are respectively arranged corresponding to the shaft heads of the cross shafts.

Description

Technical Field

[0001] The invention relates to a processing technology for a high-strength and lightweight cross shaft, and belongs to the technical field of universal joint transmission shafts. Background Art

[0002] The cross-joint transmission shaft utilizes the characteristics of its mechanism to make the two shafts not on the same axis. When there is an angle between the axes, the two connected shafts can rotate continuously and reliably transmit torque and motion. The biggest feature of the universal coupling is that its structure has a large angular compensation capability, compact structure, high transmission efficiency, and the angle between the two axes of universal couplings of different structural types is different, generally between 5° and 61°.

[0003] The cross shaft currently on the market starts from raw materials, undergoes forging and pressing, and then adopts normalizing treatment to refine the grain size and facilitate cutting. It is then turned, that is, the four shaft heads are turned, and a special positioning process is used for one-time turning, and the middle cross hole is drilled, carburized and quenched, and then the four shaft heads and the cross shaft end face are ground.

[0004] In view of this, a cross-joint drive shaft and a retaining spring locking mechanism thereof are disclosed in the patent document with application number 202122377438.X. The failure parts of the cross shaft of conventional products are concentrated at the large radius of the root or the intersection with the adjacent blank part. By increasing the diameter of the main body and increasing the diameter of the large radius of the root, the large radius of the root after machining reaches the diameter of the main body, eliminating the influence of other factors such as blank forming factors on product stress. The conventional process method is to grind the large radius of the root, and the grinding of the large radius of the root will affect its service life. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a processing technology for a high-strength and lightweight cross shaft with a reasonable structural design.

[0006] The technical solution adopted by the present invention to solve the above-mentioned problem is: a processing technology of the high-strength and lightweight cross shaft, wherein the high-strength and lightweight cross shaft comprises a cross shaft body and four cross shaft heads, wherein the four cross shaft heads are arranged in a circular array and are integrally structured with the cross shaft body, wherein the axes of adjacent cross shaft heads are vertically arranged, wherein the four cross shaft heads are respectively a first shaft head, a second shaft head, a third shaft head and a fourth shaft head, wherein the first shaft head is coaxially arranged with the third shaft head, and the second shaft head is coaxially arranged with the fourth shaft head, wherein the structural feature is that four positioning bosses are respectively arranged on both sides of the cross shaft body, and each of the four positioning bosses on each side is arranged correspondingly to a cross shaft head; The processing technology is as follows: turning the outer circle, drilling and piercing, carburizing and quenching, grinding the outer circle and grinding the end face. When turning the outer circle, use a V-shaped fixture to clamp and position the positioning boss, and then turn the end faces, journal outer circles, No. 1 step outer circles, No. 2 step outer circles, transition fillets and large root fillets of the four cross shaft heads respectively. At the position where the large root fillet is connected to the No. 2 step outer circle, turn a root digging outer circle tangent to the large root fillet. The design diameter of this root digging outer circle is less than or equal to the finished product outer circle diameter of the No. 2 step outer circle, and there is a processing allowance after turning. In terms of process design, the large root fillet and the root digging outer circle are not ground in the later stage to ensure the roughness of the large root fillet and the root digging outer circle, and then drill four inner chamfers on the end faces of the four cross shaft heads respectively; When drilling the through holes, cross-shaped through holes are drilled along the axes of the first and third shaft heads, and the axes of the second and fourth shaft heads for oil passage; During carburizing and quenching, first enter the pre-oxidation furnace for degreasing, the heating temperature is 350±10℃; then carburize according to the carburizing and quenching process curve, after the carburizing cycle, enter the quenching oil tank for quenching, the quenching oil temperature is 65±5℃; after cleaning again, the cleaning liquid temperature is 65±5℃; finally, after cleaning, turn to tempering, the tempering temperature is 170±10℃, and the duration is 300min; When grinding the outer circle, a CNC forming grinding wheel centerless grinder is used to grind the outer circle of the journal of the first and third shaft heads, the outer circle of the first step, the outer circle of the second step, and the transition fillet, and the machining allowance is ground off, and the design diameter of the outer circle of the root digging reaches the finished outer circle diameter of the outer circle of the second step. In the forming grinding wheel grinding setting, the grinding wheel at the end is ground into a fillet, so that the end where the diameter of the outer circle of the root digging connects with the finished outer circle diameter of the outer circle of the second step has a smooth transition without residual steps, and then the cross axis is rotated 90 degrees, and then the outer circle of the journal of the second and fourth shaft heads, the outer circle of the first step, the outer circle of the second step, and the transition fillet are ground off, and the machining allowance is ground off, and the design diameter of the outer circle of the root digging reaches the finished outer circle diameter of the outer circle of the second step. In the forming grinding wheel grinding setting, the grinding wheel at the end is ground into a fillet, so that the end where the diameter of the outer circle of the root digging connects with the finished outer circle diameter of the outer circle of the second step has a smooth transition without residual steps; When grinding the end faces, use several end face grinders to grind the end faces of the first and third shaft heads, then rotate the cross axis 90 degrees, and then grind the end faces of the second and fourth shaft heads.

[0007] Furthermore, the technical requirements for carburizing and quenching are surface hardness: HRC60-64, core hardness: HRC30-45; hardened layer depth: 1.0-1.4mm at 550HV1; according to standard GB / T9450-2005; retained austenite level is 1-4; carbide level is 1-4; martensite level is 1-5; according to standard GB / T25744-2010.

[0008] Furthermore, the material of the high-strength and lightweight cross shaft is alloy steel.

[0009] Furthermore, the machining allowance includes the reverse cut fillet, reverse cut bevel and grinding part.

[0010] Compared with the prior art, the present invention has the following advantages: the processing technology of the high-strength and lightweight cross shaft mainly reflects that the large radius of the root is machined before the heat treatment carburizing and quenching to ensure the roughness of the large radius of the root, and the large radius of the root is not ground after the heat treatment carburizing and quenching, because grinding at the root position is prone to grinding burns, which has a greater impact on the strength of the product. At the same time, the large radius of the root is not ground, and the carburized layer is maintained and retained, so the strength is guaranteed at the concentrated failure location. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a schematic diagram of the process flow of the high-strength and lightweight cross shaft according to an embodiment of the present invention.

[0012] Figure 2 It is a schematic structural diagram of the outer circle of a high-strength and lightweight cross axle according to an embodiment of the present invention.

[0013] Figure 3 yes Figure 2 The enlarged structural diagram of part A (before grinding the outer circle) is shown in the figure.

[0014] Figure 4 It is a schematic structural diagram of a high-strength and lightweight cross-axis drill for perforating a hole according to an embodiment of the present invention.

[0015] Figure 5 yes Figure 4 Schematic diagram of the BB cross-section structure.

[0016] Figure 6 yes Figure 5 Schematic diagram of the local sampling structure in .

[0017] Figure 7 yes Figure 6 Schematic diagram of the P-direction structure.

[0018] Figure 8 yes Figure 2 Schematic diagram of the structure of part A (after grinding the outer circle).

[0019] Fig. 9 It is a schematic diagram of the exploded structure of a cross shaft installed in a V-shaped clamp according to an embodiment of the present invention.

[0020] Fig.10 It is a schematic diagram of a push rod furnace carburizing and quenching process curve according to an embodiment of the present invention.

[0021] In the figure: cross shaft body 1, cross shaft head 2, positioning boss 3, root large fillet 4, journal outer circle 5, end face 6, inner chamfer 7, No. 1 step outer circle 81, No. 2 step outer circle 82, through hole 9, V-shaped fixture 10, root outer circle 11, reverse cut fillet 12, transition fillet 13, reverse cut bevel 14, grinding part 15, The first shaft head 21, the second shaft head 22, the third shaft head 23, the fourth shaft head 24, DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and by way of examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0023] Example

[0024] See also Figures 1 to 10 As shown, it should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, if there are references to terms such as "upper", "lower", "left", "right", "middle" and "one" in this specification, they are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0025] The processing technology of the high-strength and lightweight cross shaft in this embodiment, the high-strength and lightweight cross shaft comprises a cross shaft body 1 and four cross shaft heads 2, the four cross shaft heads 2 are arranged in a circular array and are arranged as an integrated structure with the cross shaft body 1, the axes of adjacent cross shaft heads 2 are arranged vertically, the four cross shaft heads 2 are respectively a first shaft head 21, a second shaft head 22, a third shaft head 23 and a fourth shaft head 24, the first shaft head 21 is coaxially arranged with the third shaft head 23, the second shaft head 22 is coaxially arranged with the fourth shaft head 24, four positioning bosses 3 are respectively arranged on both sides of the cross shaft body 1, and the four positioning bosses 3 on each side are respectively arranged corresponding to a cross shaft head 2; the material of the high-strength and lightweight cross shaft is high-quality alloy steel.

[0026] The processing technology is as follows: turning the outer circle, drilling and piercing, carburizing and quenching, grinding the outer circle and grinding the end face.

[0027] When turning the outer circle, a V-shaped clamp 10 is used to clamp and position the positioning boss 3, and then the end faces 6, the outer circle 5 of the journal, the outer circle 81 of the first step, the outer circle 82 of the second step, the transition radius 13 and the large root radius 4 of the four cross shaft heads 2 are turned respectively. At the position where the large root radius 4 is connected to the outer circle 82 of the second step, a root digging outer circle 11 tangent to the large root radius 4 is turned. The design diameter of this root digging outer circle 11 is less than or equal to the finished product outer circle diameter of the second step outer circle 82, but the design diameter is less than 0.10mm, and there is a machining allowance after turning, wherein the machining allowance includes the reverse cut radius 12, the reverse cut bevel 14 and the grinding part 15. In the process design, the large root radius 4 and the root digging outer circle 11 are not ground in the later stage to ensure the roughness of the large root radius 4 and the root digging outer circle 11, and then four inner chamfers 7 are drilled on the end faces 6 of the four cross shaft heads 2 respectively.

[0028] When drilling the through holes, cross-shaped through holes 9 are drilled along the axes of the first shaft head 21 and the third shaft head 23 , and the axes of the second shaft head 22 and the fourth shaft head 24 for oil passage.

[0029] During carburizing and quenching, the push rod furnace carburizing and quenching process is adopted, and the parts enter the pre-oxidation furnace for degreasing to remove the oil film and oxide film on the surface of the parts, and the heating temperature is 350±10℃; after the pre-oxidation is completed, carburizing is carried out according to the carburizing and quenching process curve. The methanol flow rate during the whole process is 1±0.2L / h. The parts enter the first zone and the temperature is raised to 860±9℃, and the cycle time is 90min; the parts enter the second zone, the temperature is raised to 910±9℃, the carbon potential is 0.90±0.05C%, and the cycle time is 120min; the parts enter the third zone, the temperature is raised to 925±9℃, the carbon potential is 1.0±0.05C%, and the cycle time is 150min; the parts enter the fourth zone, the temperature is raised to 925±9℃, the carbon potential is 1.0±0.05C%, and the cycle time is 150min. The temperature is 925±9℃, the carbon potential is 1.1±0.05C%, and the cycle time is 90min; the part enters zone 5, the temperature drops to 910±9℃, the carbon potential is 0.9±0.05C%, and the cycle time is 150min; the part enters zone 6, the temperature drops to 860±9℃, the carbon potential is 0.8±0.05C%, and the cycle time is 150min; after the carburizing cycle, it enters the quenching oil tank for quenching at 860±9℃, the quenching oil temperature is 65±5℃, and the quenching holding time is 30-60min; after cleaning, the cleaning liquid temperature is 65±5℃; finally, after cleaning, it is transferred to the tempering zone, the tempering temperature is 170±10℃, and the duration is 300min.

[0030] When grinding the outer circle, a CNC forming grinding wheel centerless grinder is used to grind the journal outer circle 5, the No. 1 step outer circle 81, the No. 2 step outer circle 82, and the transition fillet 13 of the first shaft head 21 and the third shaft head 23, and the machining allowance is ground off, and the design diameter of the digging root outer circle 11 reaches the finished outer circle diameter of the No. 2 step outer circle 82. In the forming grinding wheel grinding setting, the grinding wheel at the end is ground into a fillet, so that the end where the diameter of the digging root outer circle 11 and the finished outer circle diameter of the No. 2 step outer circle 82 meet is smoothly transitioned without residue. Step, then rotate the cross axis 90 degrees, and then grind the shaft neck outer circle 5, the No. 1 step outer circle 81, the No. 2 step outer circle 82, and the transition fillet 13 of the second shaft head 22 and the fourth shaft head 24, and grind off the machining allowance, and the design diameter of the root outer circle 11 reaches the finished outer circle diameter of the No. 2 step outer circle 82. In the forming grinding wheel grinding setting, the end is ground into a fillet, so that the end where the diameter of the root outer circle 11 meets the finished outer circle diameter of the No. 2 step outer circle 82 has a smooth transition without residual steps.

[0031] When grinding the end faces, several end face grinders are used to grind the end faces 6 of the first shaft head 21 and the third shaft head 23 , and then the cross axis is rotated 90 degrees, and then the end faces 6 of the second shaft head 22 and the fourth shaft head 24 are ground.

[0032] Technical requirements for carburizing and quenching: surface hardness: HRC60-64, core hardness: HRC30-45; hardened layer depth: 1.0-1.4mm at 550HV1; according to standard GB / T9450-2005; retained austenite level is 1-4; carbide level is 1-4; martensite level is 1-5; according to standard GB / T25744-2010.

[0033] Specifically, the high-strength lightweight cross shaft forms a machining allowance on the outer circle 82 of the second step when turning the outer circle. The machining allowance includes the reverse cut fillet 12, the reverse cut bevel 14, and the grinding portion 15. Usually, the angle α of the reverse cut bevel 14 is equal to 20°. When grinding the outer circle, the machining allowance is ground off (that is, Figure 3 The middle section line indicates that the machining allowance needs to be ground off. Figure 8 As shown), the large root fillet 4 does not need to be ground on the outer circle, and the large root fillet 4 is not ground. According to the basis of turning forming, the grinding length is to the position of the reverse tangent fillet 12 and the reverse tangent bevel 14, so that the stroke here is more consistent. After stress analysis, there is no stress influence here.

[0034] Lightweight design is taken into consideration at the core. The cross shaft is made of high-quality alloy steel. The structural design has been analyzed by CAE, especially the parts in contact with needle bearings and oil seals adopt a low-stress design. A better oil seal structure design is adopted with good sealing performance, which makes the universal joint maintenance-free and increases the service life of the universal joint.

[0035] The structure adopts a stable positioning processing structure while increasing the diameter of the middle body and removing excess structural materials in low-stress areas, so that the overall strength of the product will not be reduced. By adding process methods, the overall strength performance of the product is improved by more than 25% and the weight of the product is reduced by more than 10%.

[0036] The biggest feature of this new universal joint is that it saves raw materials, improves productivity, reduces the amount of cutting and processing of parts, thereby greatly reducing the cost of parts, and has many excellent properties such as sufficient impact toughness and wear resistance. Because it can withstand a large load, it is suitable for heavy load, high energy, and high load occasions.

[0037] The positioning boss 3 can be used to achieve positioning when assembled with the V-shaped clamp 10. At the same time, the positioning boss 3 is a discontinuous circular structure, which can save raw materials.

[0038] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the present invention. All equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. Technicians in the technical field of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A processing technology for a high-strength and lightweight cross shaft, the high-strength and lightweight cross shaft comprising a cross shaft body (1) and four cross shaft heads (2), the four cross shaft heads (2) being arranged in a circular array and being arranged as an integral structure with the cross shaft body (1), the axes of adjacent cross shaft heads (2) being arranged perpendicularly, the four cross shaft heads (2) being respectively a first shaft head (21), a second shaft head (22), a third shaft head (23) and a fourth shaft head (24), the first shaft head (21) and the third shaft head (23) being arranged coaxially, the second shaft head (22) and the fourth shaft head (24) being arranged coaxially, characterized in that: Four positioning bosses (3) are respectively arranged on both sides of the cross shaft body (1), and the four positioning bosses (3) on each side are respectively arranged corresponding to a cross shaft head (2); The processing technology is as follows: turning the outer circle, drilling and piercing, carburizing and quenching, grinding the outer circle and grinding the end face. When turning the outer circle, a V-shaped fixture (10) is used to clamp and position the positioning boss (3), and then the end faces (6), the outer circles of the journals (5), the outer circles of the first step (81), the outer circles of the second step (82), the transition fillets (13) and the large fillets (4) of the four cross shaft heads (2) are turned respectively. At the position where the large fillet (4) of the root is connected to the outer circle of the second step (82), a root digging outer circle (11) tangent to the large fillet (4) of the root is turned. The design diameter of the root digging outer circle (11) is less than or equal to the finished product outer circle diameter of the outer circle of the second step (82), and there is a machining allowance after turning. In the process design, the root large fillet (4) and the root digging outer circle (11) are not ground in the later stage to ensure the roughness of the root large fillet (4) and the root digging outer circle (11), and then four inner chamfers (7) are drilled on the end faces (6) of the four cross shaft heads (2); When drilling the through holes, cross-shaped through holes (9) are drilled along the axes of the first shaft head (21), the third shaft head (23), and the axes of the second shaft head (22), and the fourth shaft head (24) for oil passage; During carburizing and quenching, the steel first enters the pre-oxidation furnace for degreasing; then carburizing is performed, and after the carburizing cycle, it enters the quenching oil tank for quenching; then it is cleaned again; finally, after cleaning, it is transferred to tempering; When grinding the outer circle, a CNC shaped grinding wheel centerless grinder is used to grind the outer circle of the journal (5), the outer circle of the first step (81), the outer circle of the second step (82), and the transition fillet (13) of the first shaft head (21) and the third shaft head (23), and the machining allowance is ground off, so that the design diameter of the root outer circle (11) reaches the finished outer circle diameter of the second step outer circle (82), and in the shaping grinding wheel grinding setting, the end is ground into a fillet, so that the end where the diameter of the root outer circle (11) and the finished outer circle diameter of the second step outer circle (82) are connected is smoothly transitioned without residue Step, then rotate the cross shaft 90 degrees, grind the journal outer circle (5), the first step outer circle (81), the second step outer circle (82), and the transition fillet (13) of the second shaft head (22) and the fourth shaft head (24), and grind off the machining allowance, so that the design diameter of the root outer circle (11) reaches the finished outer circle diameter of the second step outer circle (82), and in the forming grinding wheel grinding setting, the end is ground into a fillet, so that the end where the diameter of the root outer circle (11) and the finished outer circle diameter of the second step outer circle (82) are connected is smoothly transitioned without residual steps; When grinding the end faces, a plurality of end face grinders are used to grind the end faces (6) of the first shaft head (21) and the third shaft head (23), and then the cross axis is rotated 90 degrees, and then the end faces (6) of the second shaft head (22) and the fourth shaft head (24) are ground.

2. The processing technology of the high-strength and lightweight cross shaft according to claim 1 is characterized in that: Technical requirements for carburizing and quenching: surface hardness: HRC60-64, core hardness: HRC30-45; hardened layer depth: 1.0-1.4mm at 550HV1; according to standard GB / T9450-2005; retained austenite level is 1-4; carbide level is 1-4; martensite level is 1-5; according to standard GB / T25744-2010.

3. The processing technology of the high-strength and lightweight cross shaft according to claim 1 is characterized in that: The material of the high-strength and lightweight cross shaft is alloy steel.

4. The processing technology of the high-strength and lightweight cross shaft according to claim 1 is characterized in that: The machining allowance includes the reverse cut fillet (12), the reverse cut bevel (14) and the grinding part (15).

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